1. Field
The present invention relates to an apparatus for locking the steering shaft of a motor-vehicle against rotation, using a locking bolt which can be axially reciprocated within a housing by a to-and-fro rotatable control element between a locked position and a release position. The locking bolt is fixed in the locked position by means of a spring-loaded securing element displaceably supported in the housing that, on account of the spring load, enters a lateral recess of said locking bolt, and that, to be moved out of said recess against the spring load applied to it, cooperates with the control element for the locking bolt.
2. Related Art
Such apparatus for irrotationally locking motor-vehicle steering shafts are known (German publication 1,780,563; British publication 2,298,229 A; German patent 196 53 860 C1). The control element driving the locking bolt in these devices is a control cam pivotable to-and-fro about an axis perpendicular to the locking bolt's longitudinal axis, the control cam co-operating through an eccentric with the locking bolt and being driven by a key-actuated locking cylinder coaxial with the control cam's pivot axis (German publication 1,780,563; British publication 2,298,229 A) or by a reversible electric motor (German patent 196 53 860 C1). The securing element fixing the locking bolt in its locked position against unauthorized displacement into its release position, so that the motor-vehicle steering shaft may be rotated, is constituted by a single-arm lever which is pivotably supported at one end about an axis extending parallel to the locking bolt's longitudinal axis (German publication 1,780,563 FIGS. 1 through 6) or an axis parallel to the pivot axis of the control cam (British publication 2,298,229 A; German patent 196 53 860 C1) while being spring loaded in order to enter at its other end the lateral recess of the locking bolt, and comprising between its two ends a lateral arm resting against the control cam in order to be pivoted against the spring load out of the locking bolt's recess when the control cam is pivoted to drive the locking bolt out of the locked position into the release position.
Moreover, it is known in the art related to apparatus for locking a motor vehicle steering shaft against rotation by means of a locking bolt which is axially displaceable in a housing to-and-fro between a locked position and a release position, to fix said locking bolt in its locked position using a spring-loaded securing pin axially displaceable within said housing and cooperating with a lateral recess of the locking bolt when part of the housing is broken off. The securing pin is supported by a retaining wire or retaining pin axially displaceable in the housing parallel to the locking bolt against the spring load on said securing pin, said wire or pin cooperating at its end located away from the securing pin with the locking cylinder driving the locking bolt or with the control cam controlling the locking bolt and connected to the locking cylinder's core in order to move axially and to release the securing pin in the event the housing part enclosing the locking cylinder and possibly enclosing the control cam is broken off, whereby, on account of its spring load, the securing pin will engage the lateral recess of the locking bolt (German patent 31 31 558 C1; German utility model 92 08 698 U1). Alternatively, the securing pin is supported against its spring load by a retaining arm projecting from the housing in the inside thereof and releasing the securing pin to enter the lateral recess of the locking bolt due to said spring load when the housing part fitted with the retaining arm is removed (German publication 100 41 984 A1).